The present invention relates to a method and system for determining the identity of a system user. More specifically, the present invention pertains to a method and system for deriving the identity of a subscriber of a communications system for use in providing services to the subscriber.
The communications industry currently provides consumers with a wide array of new and/or enhanced communications technologies. The Global System for Mobile Communications (GSM), for instance, provides traditional circuit-switched communication to its subscribers. Circuit-switched systems allocate a fixed resource to a subscriber when making a call. The resource remains allocated even during idle periods in which the subscriber is transmitting no data. In contrast, the more recently developed General Packet Radio Service (GPRS) system provides packet-switched communication to its subscribers. Packet-based systems utilize communication resources only when information is being transmitted over the network. Further background details on GSM-compatible technology can be found in Lawrence Harte et al., GSM Superphones, McGraw-Hill, 1999. Further background details on the GPRS standard may be found in Christian Bettstetter et al., xe2x80x9cGSM Phase 2+General Packet Radio Service GPRS: Architecture, Protocols, and Air Interface,xe2x80x9d IEEE Communications Surveys,  less than  less than http: // www.comsoc.org/pubs/surveys greater than  greater than , Third Quarter 1999, Vol. 2, No. 2.
In addition, the Internet (which uses packet data protocol) and other data communication networks (e.g., Intranets) now provide a wide variety of services to consumers. Most consumers continue to interface with the Internet using personal computers. More specifically, a user typically interfaces with these networks by dialing a modem pool to connect to a server. From there, the user has access to both local and global data networks. Browsers, such as Microsoft Explorer(trademark) and Netscape Navigator(trademark), allow the user to navigate on the Internet and switch between Internet pages or addresses.
Some efforts have been made in recent years to provide means for interfacing between different communication technologies and/or services. However, different communication services have generally evolved along independent paths, without giving adequate consideration to compatibility issues. It has therefore often proven challenging to provide an effective interface between these systems or to share information between these systems. For instance, service providers and communications operators are typically hesitant to release information concerning their subscribers"" identities to other, non-affiliated, service providers.
For example, a GSM telephone forwards a GSM internal identification number to the communication system when it makes a call. This number is referred to as the Internal Mobile Subscriber Identity (IMSI) number. The communications system associates this number with the subscriber""s public telephone number. This public number is formally referred to as the Mobile Subscriber Integrated Service Digital Network number (MSISDN). This protocol has a number of drawbacks. For instance, other service providers do not have access to the mappings between the secret and public identification numbers. This makes it difficult for these other service providers to provide supplemental services to the subscribers during the use of their communication devices.
One solution to the above problem would be to simply disclose the mappings of public and secret identities to all interested parties. However, in today""s information age, many subscribers and operators are reluctant to divulge personal information over the Internet (and other public networks). There remains a general concern regarding invasion of privacy issues, and specific concerns regarding credit fraud and related issues. Accordingly, the above-identified solution may not be fully satisfactory.
There is therefore a need to provide more effective techniques for interfacing between different communication technologies, and in particular for conveying subscriber identity information between different communication technologies.
The technique disclosed herein addresses the above-identified problems. In accordance with one embodiment of the technique, a data server derives information regarding the identities of users placing calls in a circuit-switched communications network. It performs this task by initially establishing at least one known and trusted identity xe2x80x9cseed.xe2x80x9d This trusted identity is stored in a xe2x80x9cknown list.xe2x80x9d The data server then uses the trusted identity seed, in conjunction with information regarding calls placed in the circuit-switched communication network, to derive additional user identities. The data server stores the derived identities in the known list. The derived user identities also serve as new xe2x80x9cseedsxe2x80x9d for uncovering additional user identities. In this fashion, the data server may quickly supply the identities of unknown users without having access to the internal databases maintained by the circuit switched communication system.
In one particular embodiment, the identities are defined by a pairing of secret and public identities used by the circuit-switched communications network to identify its subscribers (e.g., IMSI and MSISDN identification numbers, respectively).
Further, a user device may encrypt its secret identification number before transmitting it to the data server to maintain the secrecy of this information.
Further, the data server can additionally verify that the user identities stored in the known list remain valid. The data server can be configured to invalidate or correct inaccurate entries.